org.eclipse.e4.core.di.InjectionException: java.lang.NullPointerException - eclipse

Question

Here's the issue. I created a sample Eclipse 4 (Luna) application using the wizard. Everything worked fine. I decide to move the user interfaces to a dedicated plugin. I created the new plug-in, moved all the classes to the new plug-in and refactored the Eclipse Application Model, the product and plug-in configuration. Now when I try to launch the Eclipse product, I'm getting this Dependency Injection exception. When I debug, I'm noticing that all of the UI component variables have null values:
package my.company.ui.parts;
import javax.annotation.PostConstruct;
import javax.inject.Inject;
import org.eclipse.e4.ui.di.Focus;
import org.eclipse.e4.ui.di.Persist;
import org.eclipse.e4.ui.model.application.ui.MDirtyable;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Text;
public class SamplePart {
private Text txtInput;
private TableViewer tableViewer;
#Inject
private MDirtyable dirty;
#PostConstruct
public void createComposite(Composite parent) {
parent.setLayout(new GridLayout(1, false));
txtInput = new Text(parent, SWT.BORDER);
txtInput.setMessage("Enter text to mark part as dirty");
txtInput.addModifyListener(new ModifyListener() {
#Override
public void modifyText(ModifyEvent e) {
dirty.setDirty(true);
}
});
txtInput.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
tableViewer = new TableViewer(parent);
tableViewer.add("Sample item 1");
tableViewer.add("Sample item 2");
tableViewer.add("Sample item 3");
tableViewer.add("Sample item 4");
tableViewer.add("Sample item 5");
tableViewer.getTable().setLayoutData(new GridData(GridData.FILL_BOTH));
}
#Focus
public void setFocus() {
tableViewer.getTable().setFocus();
}
#Persist
public void save() {
dirty.setDirty(false);
}
}
The exception is thrown setFocus() method because the value of the tableViewer variable is null. Here's the stack trace:
!ENTRY org.eclipse.e4.ui.workbench 4 0 2014-07-10 16:40:26.368
!MESSAGE Failed to grant focus to element
!STACK 0
org.eclipse.e4.core.di.InjectionException: java.lang.NullPointerException
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:62)
at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:247)
at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:225)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:107)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.focusGui(PartRenderingEngine.java:795)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.activate(PartServiceImpl.java:679)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.switchPerspective(PartServiceImpl.java:572)
at org.eclipse.e4.ui.workbench.renderers.swt.PerspectiveStackRenderer.showTab(PerspectiveStackRenderer.java:127)
at org.eclipse.e4.ui.workbench.renderers.swt.LazyStackRenderer$1.handleEvent(LazyStackRenderer.java:66)
at org.eclipse.e4.ui.services.internal.events.UIEventHandler$1.run(UIEventHandler.java:40)
at org.eclipse.swt.widgets.Synchronizer.syncExec(Synchronizer.java:187)
at org.eclipse.swt.widgets.Display.syncExec(Display.java:4734)
at org.eclipse.e4.ui.internal.workbench.swt.E4Application$1.syncExec(E4Application.java:218)
at org.eclipse.e4.ui.services.internal.events.UIEventHandler.handleEvent(UIEventHandler.java:36)
at org.eclipse.equinox.internal.event.EventHandlerWrapper.handleEvent(EventHandlerWrapper.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:1)
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
at org.eclipse.equinox.internal.event.EventAdminImpl.dispatchEvent(EventAdminImpl.java:135)
at org.eclipse.equinox.internal.event.EventAdminImpl.sendEvent(EventAdminImpl.java:78)
at org.eclipse.equinox.internal.event.EventComponent.sendEvent(EventComponent.java:39)
at org.eclipse.e4.ui.services.internal.events.EventBroker.send(EventBroker.java:81)
at org.eclipse.e4.ui.internal.workbench.UIEventPublisher.notifyChanged(UIEventPublisher.java:59)
at org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify(BasicNotifierImpl.java:374)
at org.eclipse.e4.ui.model.application.ui.advanced.impl.PerspectiveStackImpl.setSelectedElement(PerspectiveStackImpl.java:135)
at org.eclipse.e4.ui.model.application.ui.advanced.impl.PerspectiveStackImpl.setSelectedElement(PerspectiveStackImpl.java:1)
at org.eclipse.e4.ui.workbench.renderers.swt.LazyStackRenderer.postProcess(LazyStackRenderer.java:103)
at org.eclipse.e4.ui.workbench.renderers.swt.PerspectiveStackRenderer.postProcess(PerspectiveStackRenderer.java:77)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:678)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:766)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$2(PartRenderingEngine.java:737)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$7.run(PartRenderingEngine.java:731)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:715)
at org.eclipse.e4.ui.workbench.renderers.swt.SWTPartRenderer.processContents(SWTPartRenderer.java:68)
at org.eclipse.e4.ui.workbench.renderers.swt.WBWRenderer.processContents(WBWRenderer.java:664)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:674)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:766)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$2(PartRenderingEngine.java:737)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$7.run(PartRenderingEngine.java:731)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:715)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1074)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1032)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:148)
at org.eclipse.e4.ui.internal.workbench.swt.E4Application.start(E4Application.java:164)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:382)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:236)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:648)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:603)
at org.eclipse.equinox.launcher.Main.run(Main.java:1465)
at org.eclipse.equinox.launcher.Main.main(Main.java:1438)
Caused by: java.lang.NullPointerException
at com.boeing.ccts.mpa.workbench.planner.ui.parts.SamplePart.setFocus(SamplePart.java:52)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55)
... 60 more
I read on another post that is has something to do with the annotations which also leads to believe it's a Dependency Injection issue. Not sure how to fix it. Any help would be appreciated.

Answer 1

Check if you have different versions of javax.annotation running. You can use the OSGi console and command packages javax.annotation to verify whether this holds true. I once experienced that problem with similar effects that you see: Two bundles were using different versions of an annotation so one wouldn't recognize the annotations used in the other because different bundles have different class loaders.